MEPS 521:117-128 (2015)  -  DOI: https://doi.org/10.3354/meps11125

ABSTRACT: Understanding behavioral changes is important when examining the impacts of rapid environmental change, particularly when critical resources such as protective shelters become locally limited during habitat loss events. In portions of Florida Bay (Florida, USA), cyanobacterial blooms have reduced the availability of large sponges, an important shelter for juvenile Caribbean spiny lobster Panulirus argus. We examined whether juvenile lobsters from regions with and without sponge shelters differed in: (1) aggressive and gregarious behaviors; (2) den use, den sharing, and den fidelity before and after shelter loss; and (3) dispersal from sites with and without artificial shelters. In laboratory experiments where individuals were paired with similar-size conspecifics, habitat type had no influence on aggression and gregariousness, but larger lobsters were more aggressive and shared dens less frequently than smaller lobsters. When these same individuals were placed into groups of 20 in a mesocosm and exposed to shelter loss, individuals from habitats with sponges showed a greater decrease in den use and den sharing than individuals from habitats without sponges. After shelter loss, large lobsters decreased their den use, den sharing, and den fidelity more than small lobsters. When individuals were released at their point of capture in Florida Bay, large individuals were resighted less often than small individuals. This study suggests that lobsters from habitats without sponges may respond differently to future shelter loss and that size plays an important role in determining whether juvenile spiny lobsters share shelters or disperse.

KEY WORDS: Caribbean spiny lobster · Social behavior · Panulirus argus · Aggression · Gregariousness · Sponge mortality